Automatic drilling spider



Jan. .19, 1937. wJA'. ABEGG AUTOMATIC DRILLING SPIDER Filed Aug. 19,.1955 4 Sheis-Sheet 1 INVENTOR WALT/5A A. A5666 A TTORNE Y Jan.19,-19 1.Q ABEGG 2,068 217 AUTOMATIC DRILLING SPIDER Filed Aug. 19, 1935 4Sheets-Sheet 3 INVENTOR wmm? 0. 05500 ATTORNEY Patented Jan. 19, 1937PATENT OFFICE AUTOMATIC DRILLING SPIDE Walter A. Abegg, Los Angeles,Calif., assignor of one-half to Baldwin Reinhold, Los Angeles,

Calif.

Application August 19, 1935, Serial No. 36,847 i 3 Claims.

This invention relates to well drilling apparatus, and particularlypertains to automatic spiders fordrill slips.

In carrying out rotary well drilling operations it is necessary thatmeans he provided to grip the drill string as it is being lowered intothe well or withdrawn therefrom, and to support thesame against.vertical movement with relation .to the rotary table at such times. Theusual method of accomplishing this result is to insert drill slips intoa spider, sometimes called a masterloushing or table bushing, carriedupon the rotary table, which slips are formed withserratedjgrippingfaces to engage the surface of the drillstring, orcasing, and tapered back faces by which the slips will be wedged intoengaging position and will hold the'drill string firmly at such times.In the usual construction of drill slips the slips, are individuallylifted and lowered manually. Theyare of necessity ofconsiderableweighthmaking them unwieldy to handle, and in viewof the fact that theymust be rapidly positioned in place and removed therefrom for thepurpose of efficient drilling, it is awkward to operate them and mayresult in injury to the.

drillingcrew and sometimes in the loss of a slip in the hole, whichwould delay drilling operations until its recovery. It is the principalobject of the present invention, therefore, to provide ,a spider anddrill slip structure for rotary tables in which thespider and the drillslips are at all times assembled, the slips being simultaneously andautomatically advanced to a gripping position and retracted therefrom bythe, movement of a single operating member which may be easilymanipulated to simultaneously advanceand retract the slips.

. The table bushing is madeup of two sections. It has been found thatdue to the wedging action of the slips, a heavy outward pressure isplaced upon the table bushing sections when pipe is being supported,this pressure being transmitted through the bushings to the rotarytable, causing undue wear of the faces of the central table opening. Itis therefore an additional object of theinvention to provide a tablebushing construction in which said spreading forces are taken up withinthe bushing itself, so those spreading forces are not transmitted tothetable,; andthe wear on. its surfaces are thus eliminated or' verymaterially reduced.

The present invention contemplates the provision of a spider mountedupon a rotary table and being designed with vertical ways within whichthe separate slips are mounted for vertical slid ing movement, the slipshaving operating means by which they are instantly moved in unison.

The invention is illustrated by way of example in the accompanyingdrawings in which:

Figure, 1 is a view in plan showing the structure with which the presentinvention is concerned and with parts broken away to more clearlydisclose the design thereof.

Fig; 2 is a view in diagram illustrating one methodof operating theslips and of counterbalancing the operation.

Fig. 3 is an enlarged view in vertical section taken through the drillspider and a slip as shown on the line 3-3 of Fig. 1, and showing theslip in its lowermost position.

Fig. 4 is a view similar to Fig. 3 showing the slip in its restingposition.

Fig. 5 is a view in plan showing the assembled structure on a rotarytable.

Fig. 6 is a view in side elevation showing the structure of Fig. 5.

Fig. '7 isan enlarged View in section showing the coupling pin on theline L-l of Fig. 1..

Fig. 8 is an enlarged view in transverse section on the line 8--8 ofFig. 8.

Referr ng more particularly toFigs. 5 and 6 in the drawings a rotarytable It is indicated. This table is. of conventional type having acentralopening therethrough to receive a drill slip spider or tablebushing generally indicated at I I in the drawings and within whichstructure a plurality of vertically moving drill slips 12 are mounted.These slips are simultaneously actuated by a lift ring l3 which isengaged by a lifting yoke l4 mounted upon a bracket l5 alongside therotary table and the outer end of which yoke is fitted with a lever arm16. This lever arm may be manually moved by imposing a weight on itsend, and, as particularly shown in Fig. 2 of the drawings, a cable llmay be attached to the free end of the lever arm It to connect thislever arm with a counterweight l8 attached to the end of the cable. Thecable may be led around a plurality of pulleys 19 and 20 forconvenience, and will thus make it possibleto quite easily swing theleverv armto simultaneouslylift the slips l2. The lever arm I6 is fittedwith a fulcrum pin 2| carried in slotted bearing seats of the bracket15. Springs 22 are attached to the fastening arms 23 of the bracket andare connected by pins 24 to the yoke 14. The position of connectionofthe opposite ends of the springs to the member 23 and the pins .24 issuch as toinsure that when the lever andyoke swingbeyond dead center ineither direction, the spring willtend to temporarily hold the yoke andthe lift ring in that particular position, and is not liable to bedisplaced accidentally in the operation of the machine. The forward endsof the arms of the yoke I4 carry trunnion pins upon which are mountedrollers 26. These rollers extend into an annular groove 2'! and liftingring l3 and make it possible to exert a lifting or lowering pressureupon the ring irrespective of whether or not the rotary table is inmovement. The ring I3 is provided with guide pins 28 which extendthrough bosses 29 on the ring l3. The upwardly extending portion 36 ofthe spider projects above the plane of the top of the rotary table l0.The body portion of the spider extends downwardly into an opening 3|formed through the rotary table. A counterbore 32 occurs at the top ofthe opening 3| and forms a shoulder 33 upon which an annular shoulder 34of the spider rests. The body of the spider I extends downwardly throughthe opening 3| and is relieved for a major-portion of its length toprevent binding or wedging between the parts. An annular portion 35occurs around the perimeter of the spider at its lower end to fit snuglywithin the bore 3| and to thus secure the spider or table bushing firmlyin place. The spider is made in two segmental halves, generallyindicated as Ma and llb. These halves are pivoted upon a vertical hingepin 36 shown in the lower left hand corner of Fig. 1 of the drawings.The two spider halves may, therefore, be withdrawn from the rotary tableand removed from an embracing position around the drill stem. The freeends of member la. and Nb are temporarily locked together by a taperedlock pin 31, which, as shown in Fig. 7 of the drawings, extendsdownwardly through taper pin-holes 38, 39 in intermeshing bosses or endformations 38 and 39, respectively, of the two spider sections. Pins 36and 31 rigidly interconnect the bushing parts Ila and Nb, when in thecondition of Figs. 1 and 7. In order to secure the lock pin 31 inposition a lock plunger 40 is mounted to reciprocate in a bore 4| formeddiametrically across the lock plunger. A spring 42 yieldably urges thelock pin 49 outwardly to set within the recess 43 formed in the boss 38.The pin 31 has an upper portion 31 which extends through a bore 44 inthe lifting ring I3 and. tends to guide the ring in its verticalmovement. A stop pin 45 extends transversely of the portion of the pin31 projecting above the lifting ring to limit the upward movement of thering.

As particularly shown in Fig. '7 of the drawings an annular groove 46 isformed around the body of the lock pin at a point above the upper faceof the spider. Directly below this groove an annular collar 4'! isformed on the pin to limit the downward movement of the pin. The groove46 provides a downwardly presented shoulder 48 be neath which a pryingmember could be positioned in the event that the pin 31 should stick inthe bores of the bosses 38 and 39 of the spider sections. The spidersections are each formed with a pair of vertical guideways 49. Theseguideways are of channel section and are suitably reinforced by a rib 50extending around their perimeters. The guideways extend radially of theassembled spider structure and of the rotary axis of the table ID. Theguide channels 46, as particularly shown in Figs. 3 and 4 of thedrawings, have a vertical wall and a lower horizontal wall. The lowerwall is formed by an inwardly extending floor portion 5| through which acenter opening 52 occurs. The center opening is bound by a downwardlyand inwardly extending guide flange 53 which has an upwardly presentedinclined face 54 and a downwardly presented inclined face 55 by whichthe opening 52 is defined. Due to this arrangement it is possible toeasily guide the drill stem and its collar through the spider and therotary table and to tend to center the drill string for operation.Mounted within each of the guideways 49 is a spider wedge block 56.These wedge blocks fit within the guide channels 59, but present aseries of inner vertically inclined faces over which drill slips 51 maymove as they shift radially from a non-wedging to wedging positions, andvice versa. The faces, as shown in Figs. 3 and 4 of the drawings, arethree in number: an uppermost inclined face 58, an intermediate inclinedface 59, and a lowermost inclined face 66. The faces 59 and 66 arerelieved throughout the portion of their upper length as indicated at 6|and 62 of the drawings. Extending vertically of the relieved portions ofthe faces is a reinforcing rib 63 which tends to strengthen the Wedgeblocks and to resist the heavy stresses and strains to which they areimposed. The drill slips 51 are formed with faces 64, 65, and 66 whichagree in angularity with the faces 58, 59, and 66 of the wedge blocks,and vertically of which said drill slips slide. The recesses 6| and 62are formed with inclined faces 68 and 69 which are in planes parallel tothe faces 65 and 66 of the drill slips. This makes it possible for theprojecting portions 16 and H of the slips, and upon which the inclinedfaces 65 and 66 occur, to move into the recesses 6| and 62 when thedrill slips are in their uppermost and retracted positions. Outwardmovement of the drill slips is limited by pins 12 and 13 which arecarried by the projecting portions 16 and H of each slip. These pinsextend horizontally from opposite sides of each of the drill slips 51and project into guide slots 14 and 15 occurring in the oppositeparallel side walls of each of the guide channels 49. The guide slots,as clearly shown in Figs. 3 and 4 of the drawings, have a lower lengthwhich extends parallel to the faces 59 and 66 of the guide blocks andupper length extending parallel to inclined faces 16 and 11. Theinclined face 15a forms a continuing face from the face 59 of the guideblock to the face 68. The inclined face 16a forms a continuing face fromthe face 66 of the guide block to the face 69. Due to this arrangementthe pins and their guide slots cooperate in maintaining the drill slipsin sliding contact with the various faces along which they move in theiroperation. The individual drill slips 5'! are each provided with alifting finger 18 one of which extends upwardly from each of the slipsand each of which terminates in an outwardly extending flange 79. Theseflanges project horizontally and radially of the assembled structure andextend into channel shaped saddles carried by the lifting ring l3. Itwill thus be evident that as the lifting ring I3 is raised or loweredits saddles will engage flange 19 on each of the lifting fingers andwill correspondingly raise and lower a drill slip while the flange 19moves vertically and reciprocates horizontally with relation to itssaddle 86. The gripping face of the drill slips may be formed asdesired, but it has been considered preferableto construct it with aplurality of removable inserts 8| characterized as having their grippingfaces serrated and as having a substantially semi-cylindrical verticalback face which seats within a vertically extending 75 groove of arcuatecross section. As shown in Figs. 3 and 4 of the drawings, it will beseen that the lower ends of the inserts are formed with toes 82 whichhook over a locking flange 83, and with their upper ends are formed toes84 which are engaged by a retaining angle 85. It is to be understoodthat various designs of wedge blocks and drill slips may be made, andthat, if desired, the spider sections may be articulately connected andassembled in other manners than shown in the drawings, without departingfrom the spirit of the invention.

In operation of the present invention the structure may be assembled ashere disclosed, it being understood that the lifting ring is also formedin two sections which are hinged upon the pins 36 and 31 so that theentire spider with the ring sections and slips may be readily placed inan assembled position around to fit within the bore 3| of the rotarytable. After this has been done, the lever IS with its yoke I4 may bemoved to swing the yoke l4 upwardly, thus lifting the ring l3 andsimultaneously lifting and radially retracting all of the drill slips51. Sections of drill string may then be lowered through the centeropening 52 of the assembled slip structure and the rotary table. When itis desired to set the drill string against vertical movement, the leverI6 may be lifted so that the lifting ring will be moved downwardly andthe drill slips 5'! will move downwardly and inwardly to wedging andgripping position. As this action takes place, the complementaryinclined faces of the wedge blocks and the drill slips will act todirect and determine the inward movement of the drill slips and willcause a wedging action to occur around the drill pipe. The guide pins 12and 13 will move along the slots 14 and I5 and will also tend to guidethe slips, as well as limit their outward movement to a wedgingposition. The slips in riding down the tapered surfaces of blocks 56 andwedgingly gripping a pipe or casing, set up lateral or horizontal forceswhich, in some cases, are very large. These lateral forces are of coursetransmitted to the halves of the table bushing, but the pins 36 and. 31take those lateral forces or spreading pressures, and thus prevent thesepressures from being imposed upon the rotary table, to very realadvantage. As previously stated, it may facilitate matters tocountterbalance the lever l6 so that weight l8 will substantially agreewith the aggregate weight of the lifting ring and the wedging slips, andso that the lever l6 may be moved with relatively small efiort. In orderto facilitate in manipulating the assembled structure eyebolts 9|] aremounted in the upper face of each of the spider sections to be engagedby spider hooks, or cables, connected with the draw-works of the wellrig.

Attention is directed to the fact that due to the backing provided thewedge members for the slips it is possible to design the structureshaving sliding planes of angles more nearly vertical than commonly used.This prevents excessive wear on the parts, makes it possible to obtainsuitable gripping action without imposing undue strain on the grippingteeth of the slips, and prevents the parts from becoming readily brokenand the teeth from being dulled.

It will thus be seen, therefore, that the invention here disclosedcomprises desirable means for maintaining an entire set of drill slipsin a permanently assembled position whereby they may be easily installedupon a rotary table and whereby the drill slips may be collectivelyoperated to grip or release a pipe or casing extending through therotary table.

While I have shown the preferred form of my invention as now known tome, it will be understoodthat various changes may be made incombination, construction, and arrangement of parts by those skilled inthe art, without departing from the spirit of my invention as claimed.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. In a rotary well drilling apparatus an automatic drill spidercomprising a spider member adapted to be operatively positioned withrelation to a rotary table, a plurality of drill slips verticallyslidable with relation to said spider member, a lifting ring engagingeach of the drill slips to move the same, operating means engaging thelifting ring to raise and lower it, said spider and ring each beingformed in two complementary sections whereby said members may bedisposed in an embracing position around a drill string or the like tobe gripped, and means articulately connecting contiguous ends of saidspider and ring sections.

2. In a rotary well drilling apparatus an automatic drill spidercomprising a spider member adapted to be operatively positioned withrelation to a rotary table, a plurality of drill slips verticallyslidable with relation to said spider member, a lifting ring engagingeach of the drill slips to move the same, operating means engaging thelifting ring to raise and lower it, said spider and ring each beingformed in two complementary sections whereby said members may bedisposed in an embracing position around a drill string or the like tobe gripped, means articulately connecting contiguous ends of said spiderand ring sections, and means for locking the opposite ends of saidspider and ring sections in their operative position.

3. In a rotary well drilling apparatus an automatic drill spidercomprising a spider member adapted to be operatively positioned withrelation to a rotary table, a plurality of drill slips verticallyslidable with relation to said spider member, a lifting ring engagingeach of the drill slips to move the same, operating means engaging thelifting ring to raise and lower it, said spider and ring each beingformed in two complementary sections whereby said members may bedisposed in an embracing position around a drill string or the like tobe gripped, means articulately connecting contiguous ends of said spiderand ring sections, and guide means whereby the ring sections and theircomplementary spider sections will swing in unison and may besimultaneously manipulated.

WALTER A. ABEGG.

